Automatic safety device



J1me 1930- CUNNINGHAM AUTOMATIC SAFETY DEVICE Filed July 24, 1925 .v w H :5 mm m x M 3 m M E 9 Patented June l0, 1930 UNITED STATES JPATENT; OFFICE LEWIS L. cUN INenAM, or MINNEAPOLIS, MINNESoTA, 'AssIGNon, BY MEsNE As SIGNMENTS, To MINNEAPOLIS-HONEYWELL nmULAToR COMPANY, or MINNE- APOLIS, MINNEsoTA, A conroaATIoN or DELAWARE AUTOMATIC sArETY DEVICE Application filed July 24, 1925. Serial No. 45,835.

This invention relates to newand useful improvements in thermally actuable devices and more particularly to the provision of such a device including an element which may have a relatively greater effective expansion or distortion than its support, so that such relative heat distortion may be employed for operation and control of various means such as is common in this art,

i. euvalves, dampers, electrical connections,

etc.

Generally, the device includes a substantial ringlike portion and a transverse strip extending across said portion and termi- 5 nally connected thereto, the strip being less thick than such portion and preferably having a section normally deformed or distorted from the normal plane or longitudinal axis of the strip so that when the strip is heated,

2 it will bend in the general direction of such initial distortion or deformation.

The invention also comprehends a support for this strip and its enclosing portion so that these parts may be positioned adjacent 26 a source of heat with the strip element more exposed to the heat thanthe enclosing portion whereby, upon heating the strip, the strip expands relatively to its enclosing portion and, upon cessation of heat the strip 30 heat is conducted to the-member. Preferably, the. strip and its associated parts are integrally formed so that they will have the same co-efiicient of expansion with the result that the relative effective expansion of these two parts will be substantially the same without regard to the initial temperature of the two parts.

The object of this invention is to provide an improved thermally actuable device.

from the following description and the accompan ing drawings and will be pointed out in t e annexed claims.

In the drawings, there has been disclosed a structure designed to carry out the various objects of the invention, but it is to be un-- Other objects of the invention will appear.

In the accompanying drawings forming part of this specification,

Figure 1 shows a vertical sectional view through the device and a mounting upon a conventional representation of a heating plant and also showing electrical connectrons;

Figure 2 is a plan view of the preferred form of strip and integral arrangement;

Figure 3 is a top plan view of a portion of the tubular mounting showing the position of the strip and ring in dotted lines;

Figure 4 is a view in vertical section showing the employment of two strips and rings and their electrical connections; and

Figure 5 is a cross-sectional view on the line 55 of Figure 4 showing the preferred arrangement 0 the strip when two are employed.

A selected form of the strip and connected support is shownv in Figure 2 as consisting of a cross-sectionally thin strip 5 which extends diametrically across a cross-sectionall thick ring 6. The strip and ring are pre erably ofvmetal and are integrally formed. A suitable metal is brass. As suggested in Figure 1, the ring is many times thicker than the strip. These parts are adapted to be mounted adjacent a source of heat so that the strip will be more exposed to the heat than the ring so that the strip will expand relatively to the ring, the heat-sensitive member 5 is herein shown integrally attached to the radiator or enclosing member or ring 6, substantially in a plane of one face of the radiator member, and diametrically thereof, the element 5 being thus offset in a direction axially of, the annular member 6. Thus the enclosing member has its major portion spaced from the member 5. In order that the strip may be distorted or bend in a predetermined direction, its major portion is given an initial distortion or deformation out of the former plane of longitudinal axis I of the strip as is suggested in Figures 1 and 4. It is therefore obvious that when the strip is hotter than the ring, the strip will expand by continuing the usual distortion rather than reversing the directionof dis- -l tortion so as to pass through the normal plane or axis of the strip.

A mode of using this novel thermally actuable device is shown in Figure 1 wherein there is employed an elongated hollow member such as the cylinder 7, adapted to be supported adjacent a source of heat, such as the boiler 8 containing any of the usual forms of heating means. This cylinder 7 is flanged or provided with lugs 9 whereby the cylinder may be securely bolted to the walls of the boiler surrounding'an aperture therein through which the cylinder 7 terminally projects. This boiler or furnace end of the cylinder 7 is open so that heat may pass within the cylinder by radiation and possibly by convection. The transverse strip 5 is placed diametrically across the outer end of the cylinder 7 and the opposite portions of the outer edgeof the cylinder are preferably provided with recesses 10 to receive the end portions of the strip (see Fig. 3). The ring 6 is given an inner diameter which makes a close lit with the periphery of the cylinder cover 11..

. One means for using this relative expansion of the strip and its ring is shown in Figure 1 wherein a threaded stem 12 is borne by the strip in insulated relation therefrom.

The particular form of mounting shown consists of a flanged plug 13 of insulating material which tightly fits the central aperture 1 1 in the strip, with the flange of the plug resting against the adjacent face of the strip. A nut 15 is mounted on the stem 12 and a washer 16 is interposed between this plug and nut. A washer 17 of insulating material abuts against the inner face of the strip adjacent the aperture 14 and its inner .face is partially covered by a metallic washer 18 and the parts are held in assembled relation by means of a nut 19 secured in threaded engagement with the stem 12whereby movement of the strip is communicated to the stem 12. The stem 12 projects through an aperture in the cover 11 and has an electrical wire 20 terminally carried thereby. The. other end of this wire 20 is connected to a binding post 21 which extends through an insulated plate 22 for electrical connection with the control wire 23. The" other control 'wire 24 is connected to a binding post 25 inwardly extending in spaced relation through the insulating p ate 22 and terminating in a contact point 26 normally in spaced relation from the contact head 27 carried on the outer end of the stem 12. The insulating plate 22 is screwed to angled brackets 30 which are also screwed 'to the ring 6.

When combustion takes place within the boiler 8, such for example, as the flame of an oil burning apparatus, heat is directed to the transverse strip 5 within the tube 7.

and is distorted in the direction of its initial deformation so that the stem 12 is outwardly pushed to effect electrical engagement of the head 27 and contact point 26 with the resultant closure of any electrical control circuit provided by the wires 23 and 24. Upon cessation of the heat, the heat of the strip 5 is conducted to its integral ring 6 so that the parts assume their relatively normal relationship whereby the electric contact between the head 27 and the point 26 is opened in order to reduce the conduction of heat between the strip and its ring, the ends of the strip adjacent the ring are preferably reduced as shown in Figure 2.

in the form shown in Figure 4:, there are employed two such rings and strips similarly carried by the tube 7. The additional similar ring 28 occupies a position reversed with respect to that of the complementary ring 6, with the result that the initial distortion of its integral transverse strip 29 is toward that of the strip 5. By this means there is provided substantially twice the relative movement obtainable by the use of a single strip. The stem 12 is carried by the strip 5 in the same manner as shown in Figure 1, but an insulating sleeve 31 is fixedly carried by the strip 29 and the stem 12 passes longitudinally through the sleeve 31. The outer end of the stem 12 projects beyond the sleeve 31 and is connected to the wire 23 and terminally provides the contact head 27. A bracket 32 of insulating material, is fixedly carried by the sleeve 31 and outwardly. extends beyond the end of the stem and its ofi'set arm 33 is apertured to support the binding post 25, electrically connected to the wire 24 and inwardly projecting to provide the complementary contact point 26 for the contact head 27. When these strips are heated, the strip 5 continues its initial distortion and its central portion outwardly bends, and the strip 29 likewise continues its initial distortion and inwardly bends. The result is, that the stem 12 is outwardly thrust while the sleeve (which carries the bracket 32 and binding post and contact 26) is inwardly thrust so that the contact head 27 and contact point 26 are moved to electrical engagement. Upon removal of the source of heat supply, the cooling of: the strips 5 and 29 causes them to move apart with the resultant moving apart of the head 27 and contact point 26 and interruption of the previously formed circuit at these points. Preferably, when two expanding effect of the heat directed to the 7 tube.

Having thus described my invention what I claim as new and desire to secure by Letters Patent, is: v

1. A device of the class described comprising a tubular member, an annular element encircling said tubular member and having a relatively large cross-section, a relatively thin heat-sensitive element enclosed by thectubular member and attached to said relatively thick annular element, and a cap closing the tubular member and having a sealing socket fitted within the annular elean annular element encirclin ment. v

2. A tubular element having a closed end,

and embracing the tubular element and aving a rela tively thin heat-sensitive element enclosed by the tubular element, and said heat-sensitive element carrying an electrical contact which slidably traverse the closed end,

1 and a second contact with which said first an annular element encirclingfand embraccontact is cooperative when the heat-sensitive element is deflected.

3. A device of the class described com prising a tubular element, an annular ele- .with which said first'contact is cooperative when the heat-sensitive element is deflected.

. ment encircling and embracing the tubular ment encircling and embracing the tubular element and having a heat-sensitive element enclosed by the tubular element, the annular and heat-sensitive elements havlng the same co-eflicient of expansion and, bein integral and bein disposed intermediate y of the ends of t e tubular element,.the said heatsensitive element being cross-sectionally thinner than the annular element.

4; A tubular element'having a closed end,

" ing the tubularelement, and having a rel- .at vely thinheat-sensitive element enclosed by thetubular element,'and said heat-sensiti ve element carrying an electrical contact whichf'slidably traverses said end, and a second contactsupported by the annular element with which said first contact is cooperativ'effwhen the heat-sensitive element. is I I posed at the outside of said tubular element 5. Atubular element having a ca closin one end, anannular element enclrc ing an embracing theftubular element and cap and having a relatively'thin heat-sensitive element-enclosed by the tubular element, and said heat-sensitive element carrying an electrical contact which slidably traverses said first contact is cooperative.

6. An elongatedtubular element having a end, and asecond contact with which saidcap closing one end, an annular element enand cap and havin I spnsitve element enc 'osed by the tubular ele- .ment adjacent the cap, said heat-sensitive circling and embracingthe tubular element a relatively thin heatelement carrying an electrical contact which slidably traverses said cap, and a second contact supported by the annular element I element, and having a relatively thin heatsensitive element enclosed by the tubular elemen't,.said element having the same coeflicient of expansion as its annular element and being integral therewith, said annular and heat-sensitive element being located intermediately of the ends of the tubular element. c p 1 9. A thermallyactuatable device comprising a tubular element, a pair of annular elements encircling andembracing the tubular element, each element having a relatively thin heat-sensitive element enclosed by the tubular element, an electric contact carried by one of the heat-sensitive elements, a tubular member of insulating material connect-- ing with the other element and slidable upon the first, said insulating element carrying a contact cooperable with the first-mentioned contact. v Q

10. A-device of the class described comprising a hollow member, a heat conducting element attached crosswise within the'member, and having an annular thickened por-- tion exposed at .the outer side ofthe memher as a conductor and radiator of heat.

11. A device'of the class described comprising an elongated tubular element, a relatively thin element of heat conductin material arranged within and crosswise 0 said tubular elementg and having a portion exand of a cross sectional area to cause a predetermined. quantity of received heat to be continually radiated and dissipated from within.

' .12.. A device of the class described 'comprising a hollow member, a heat conducting elementattached crosswise within the member, and having a thickened annular portion exposed at the outer side of the member as a conductor and radiator of heat, that end of the tube nearest the heat conducting element being closed, whereb a reater tem- 'peraturecan be maintained msi e than outside of said member, and whereby heat rewardly.

said-heat conducting. element is continua y radiated and dissipated out- 13. A device r the 61m described comprising a tubular member, an element of heat conducting material arranged within and crosswise of said member to intercept heat traveling within the member, and having a portion exposed at the outside of the member and acting as a radiator, whereby a predetermined quantity of heat received by said inner element can be continually radiated and dissipated at the outside of the tubular member.

14. A device of the class described comprising a tubular member, a relatively thin element of heat conducting material arranged within and crosswise of said member to intercept heat traveling within the member, and having a portion exposed at the outside of the member of a cross-sectional area substantially greater than the relatively thin element, whereby a predetermined quantity of heat received by said relativly thin element can be continually radiated and dissipated at the outside of the tubular member.

15. A device of the class described comprising a tubular member, an element arranged within the member and having a portion exposed at the outer side of the member and of such cross-sectional area as to cause it to act as a comparatively rapid radiator and dissipater of heat received by the inner element, the said member being closed at a point adjacent the inner element.

16. A device of the class described comprising a tubular member, an element arranged within the member and having a portion exposed at the outer side of the member and of such cross-sectional area as to cause it to act as a comparatively rapid radiator and dissipater of heat received by the inner element, the said member being closed at one end only and said element being1 arranged at a point adjacent the closed en 17. A device of the class described comprising a hollow member, a heat conducting element exposed at the outside of the member and a second .heat conducting element upon the heat-sensitive element in greater degree than upon the radiator element.

20. A radiator element, a heat-sensitive element connected thereto, and a shield arranged so that a difference intemperature between the elements can be maintained such that the heat-sensitive element will have the higher temperature.

21. A radiator element, a heat-sensitive element connected thereto, and a shield arranged to regulate the degree of impingement of radiant energy upon the elements so that the radiator element can never be raised to a temperature equal to that of the heat-sensitive element.

22. In combination with a heating device having an opening through which radiant energy can pass from within outwardly, a radiator element outside the heating device, a heat-sensitive element connected with the radiator element and arranged to be affected by radiant energy passing through the opening, and a shield arranged to permit direct impingement of radiant energy upon the heat-sensitive element but protect said radiator element from such direct impingement.

23. A radiator element, a heat-sensitive element connected thereto, and arranged so that a difference in temperature between the elements can be maintained so that the heatsensitive element will have the higher tem- .perature.

In witness whereof, I have hereunto set my hand this 13th day of July, 1925.

LEWIS L. CUNNINGHAM.

arranged within the member crosswise therei of an connected with the first mentioned heat conducting element, said elements be- 7 ing arranged at a'point intermediately the ends of the hollow member.

18. A device of the class described comprising a hollow member, a heat conducting element exposed at the outside of the member and a second heat conducting element arranged within the mmber crosswise thereof and connected with the first mentioned heat conducting elements, said elements being arranged at a point intermediately'the I ends of the hollow member, and said memter being closed at one end.

19. A radiator element, a heat sensitive element connected thereto, and a shield arranged to allow impingement of heat energy 

